abstract |
The present invention relates to an improved process for the preparation of Entacapone of formula (I): comprising a step of, condensation of 3, 4-dihydroxy-5- nitrobenzaldehyde of formula (II): with N, N-diethylcyanoacetamide of formula (III): in the presence of two component solvent system, a catalyst and optionally a phase transfer catalyst to give Entacapone of formula (I). |